Process for agglomerating particulate wood material and products obtained thereby

Abstract

The disclosure describes a process for agglomerating particulate wood material such as saw dust, wood shavings, fines, bark, tree needles, wood chips, wood dust, newspaper and cardboard material, impurities normally encountered therein and mixtures thereof. The process comprises providing a particulate wood material with a moisture content of between about 10 to 40 percent by weight calculated on a dry basis. Then, the moisture containing particulate wood material is dry mixed with dry powdered lignosulfonate to form a substantially homogeneous mixture which is compressed under a pressure of at least about 400 lbs/inch 2 until the particulate wood material is agglomerated. The product obtained is resilient, easily ignitable and combustible.

We claim: 
     
       1. Process for agglomerating particulate wood material which comprises: (a) providing essentially particulate noncarbonized wood material having a substantially homogeneously distributed moisture content throughout and substantially heterogeneous size and shape distribution, said moisture content varying between about 10 and about 40 percent by weight calculated on a dry basis;   (b) dry mixing said particulate wood material with dry powdered lignosulfonate and forming a substantially homogeneous free-flowing mixture essentially consisting of said dry powdered lignosulfonate and said particulate wood material;   (c) compressing said mixture under a pressure of as low as about 400 lbs/inch 2  until said particulate wood material is agglomerated.   
     
     
       2. Process according to claim 1, wherein said compressing is carried out by moulding. 
     
     
       3. Process according to claim 1, wherein said compressing is carried out by molding said mixture into briquettes. 
     
     
       4. Process according to claim 1, wherein said compressing is carried out by molding said mixture into logs. 
     
     
       5. Process according to claim 1, wherein said compressing is carried out by molding said mixture into boards. 
     
     
       6. Process according to claim 1, wherein said compressing is carried out by molding said mixture into aggregates. 
     
     
       7. Process according to claim 1, wherein said particulate wood material comprises saw dust, wood shavings, fines, bark, tree needles, wood chips, wood dust, newspaper and cardboard material, leaves, impurities normally encountered therein and mixtures thereof. 
     
     
       8. Process according to claim 1, wherein said moisture content is between about 10 to 35 percent by weight. 
     
     
       9. Process according to claim 8, wherein said moisture content is between about 18 to 25 percent by weight. 
     
     
       10. Process according to claim 1, wherein said moisture content is about 22 percent by weight. 
     
     
       11. Process according to claim 1, wherein said particulate wood material is mixed with about 5 to about 40 percent by weight of lignosulfonate. 
     
     
       12. Process according to claim 1, wherein said particulate wood material is mixed with about 8 to about 30 percent by weight of lignosulfonate. 
     
     
       13. Process according to claim 1, wherein said particulate wood material is mixed with about 15 to about 22 percent by weight of lignosulfonate. 
     
     
       14. Process according to claim 1, wherein said particulate wood material is mixed with about 20 percent by weight of lignosulfonate. 
     
     
       15. Process according to claim 1, wherein said lignosulfonate is selected from the group consisting of calcium lignosulfonate, desugarized calcium lignosulfonate, sodium and calcium lignosulfonate and mixtures thereof. 
     
     
       16. Process according to claim 1, wherein said lignosulfonate is calcium lignosulfonate. 
     
     
       17. Process according to claim 1, wherein dry mixing is carried out at room temperature. 
     
     
       18. Process according to claim 1, wherein compressing is carried out at 800 to 1300 lbs/inch 2  for elongated fibres. 
     
     
       19. Process according to claim 14, wherein compressing is carried out at about 2000 lbs/inch 2  for short fibres. 
     
     
       20. Process according to claim 1, wherein said particulate material includes bark. 
     
     
       21. Process according to claim 20, wherein said bark is used in amounts up to about 100 percent by weight of the wood material. 
     
     
       22. Process according to claim 3, wherein briquetting lasts 1/2 minute. 
     
     
       23. Shaped product consisting of a substantially homogeneous mixture of essentially particulate non-carbonized wood material having a moisture content between about 10 and about 40 percent by weight calculated on a dry basis and a substantially heterogeneous size and shape distribution, and dry powdered lignofulsonate, said shaped product being resilient, easily ignitable and combustible.